The present invention relates to leak detection systems for semiconductor processing equipment. More specifically, the present invention is directed to a leak sensor capable of indicating constituents of chemical leaks as well as a leak sensing system using leak sensors.
With the recent trend toward higher density semiconductor devices and an increasing number of processes, it is desirable to have more efficient and higher quality semiconductor manufacturing processes. Enhancement of the process quality, however, is highly dependent on improvement in the functionality and performance of the semiconductor manufacturing apparatuses and equipment used in these processes. Such apparatuses and equipment include, for instance, wastewater treatment equipment and chemical supply equipment. Chemical supply equipment can include pipes configured to supply various chemicals (e.g., photoresist and cleaning solution) to a semiconductor manufacturing apparatus.
In order to perform the semiconductor manufacturing processes, various equipment is connected to the semiconductor apparatus. Unfortunately, accidents frequently result from leakages occurring at equipment connection points. Although environmental safety patrols may occasionally be conducted to detect and prevent accidents caused by such leakages, it is generally difficult for people to detect minute leakages. Operators (and particularly those operators with a limited understanding of the chemicals being used) may therefore be inadvertently exposed to the chemicals. Furthermore, if the leakage is not detected and suppressed at an early stage, multiple accidents may be caused from the leakages. These accidents may include secondary or tertiary accidents from electric cables or other equipment and facilities that are damaged by the chemical leakage. As a result, semiconductor manufacturing lines may be required to be stopped for prolonged periods of time while the failure points are determined and the necessary repairs are conducted.
Some conventional leak sensing systems use a point-type leak sensor that emits a light and calculates the intensity of light reflected back to the sensor to determine when a leakage occurs. Other conventional leak sensing systems may use a wire-type leak sensor. There are two kinds of wire-type leak sensors. One wire-type leak sensor incorporates a two-wired cable that is short-circuited when a leakage occurs to sense the leakage. The other wire-type leak sensor includes a cable, wherein a resistance of the cable is determined to sense the occurrence of a leakage.
Unfortunately, conventional leak sensors are generally installed in a semiconductor apparatus or a valve box, and they are therefore unable to sense a leakage of a utility pipe. They are also generally unable to detect the kind of chemical leaked. Moreover, the light emitted by a point-type leak sensor may be absorbed by the leakage, thereby reducing the intensity of the light reflected back to the sensor. The point-type leak sensor may therefore not be able to adequately sense the occurrence of the leakage.